PitchLock

[Bill Ballard]

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At 4:07 PM +0100 12/28/03, Richard Brekne wrote:
>I dunno Isaac... perhaps its just my speakers... but I didnt notice any
>lessening of sustain, nor any less rich tone.

I don't think there's much we should expect to notice from a video 
file over the net. Or a unison that we only get to hear the first two 
seconds of. We'll have to hear reports of his live presentations to 
see just how well the coupling cleans up unisons (and all their 
richness).

Of the three samples on the video file, only the middle one (the A3 
on the CD) would pass muster. (Its 7th partial was still clear after 
two seconds.) The other two (F#4 on the L/O, and A4 on the CD) are 
improved, but no cigar. (Or at least not one I'd like to sell to a 
customer.) I hope the remaining poor quality of those unisons isn't 
due to something as simple as the third string on those notes joining 
in with the two strings, coupled or no. Or maybe a false beat in one 
of the two coupled strings. If so, that would be a sloppily executed 
presentation. If this is not the case, then we're left to wonder why 
the coupling cleaned up the unisons in the 2d sample but not the 1st 
and 3d? An unreliable technique? Then maybe he's rushing to market 
with an immature product.

The coupling model he demonstrates also raises many questions. It is 
one where the period of the Simple Harmonic Motion is adjusted by 
speaking length, but unaffected by tension. The pianos we work on 
aren't made with adjustable speaking lengths: we adjust their 
frequencies (inverse of period) by tension. At best, it is a good 
visual demonstration of how coupling can work, for people with not 
especially inquiring minds. But it doesn't offer much of a scientific 
basic for the effect he claims the coupling accomplishes.

It's also unclear exactly how this would be used, assuming it were 
100% effective. The tuning would be impossible with the clips on, so 
the clips would have to be installed after a tuning. If the piano 
already has the clips installed, they would have to be removed before 
the tuning and replaced afterwards. Does the act of coupling the 
strings change their pitch? (In his pendulum model, it did. I 
measured the frequencies of his swinging pendulums. With the unequal 
lengths, the short was short length was .729 cps, the long was, .710 
cps and coupled they were .721. Undoubtedly, in his model the 
combined frequency vaguely resembles and average of the two strings.)

This is a big question, whether coupling changes the frequencies of 
strings already in good unison. I'd guess the change in frequency is 
a function of out-of-tuneness of the strings involved. But 
unfortunately  it's far less serious a question than why two of three 
of his demo samples don't work.

Further questions in this cue are, under what circumstances is this 
expected to preserve the entire tuning. Remember, this is only a 
means of (hopefully) locking in the unisons. It has nothing to do 
with the way intervals warp with the heave and sag of a board 
changing in its moisture content. Should we assume that the clips 
HAVE to be combined with a climate control system, to really provide 
meaningful protection for the tuning. Or is this meant just to 
"batten the hatches down" against gorilla-like forces applied to the 
tuning? And if this is the case (say, Aaaahnold booking studio time 
to record "Loiue, Louie" and other rock'n'roll favorites), what good 
is a means for holding the unisons steady if this is at the expense 
of interval tuning?

Further, do the people we'd be selling this to ("piano teachers, 
school boards etc") appreciate the subtleties of the motion of 
tunings. Or do we sell this to people who, with the clips installed 
will say, becasue my piano has 'em, it must be in tune now and will 
never go out of tune? (You know the type.)

Scott is a great guy. I've learned much from him, and he has worked 
in situation that I can only dream of. I wish him well in this 
endeavor. But his internet video demos are less helpful than 
singingtone.com's. I'll wait to hear from someone who has been to a 
live presentation, to judge the merits of his idea.

Bill Ballard RPT
NH Chapter, P.T.G.

"Trust me, you've got all the equipment, You just need to read the manual"
     ...........Reese Witherspoon in "Legally Blonde"
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